Enhanced photoluminescence of single-photon emitters in nanodiamonds on a gold film

Engineering the photo-emission characteristics of single-photon emitters is crucial for the growing field of quantum technologies. We show that the photoluminescence of a single nitrogen-vacancy color center in nanodiamond could be significantly enhanced when attached to a gold film of 50 nm with preserving photophysical properties as a single photon source. The nitrogen-vacancy center on the gold film showed a decreased excited-state lifetime and a modified saturation characteristic. The photoluminescence enhancement was due to the enhanced electric field by the surface plasmon and the energy transfer from the excited state of nitrogen-vacancy centers to the surface plasmon.